Spray dispenser

ABSTRACT

A spray dispenser is provided, the spray dispenser comprising a container for holding a liquid to be dispensed and a dispensing assembly for extracting liquid from said container, the dispensing assembly comprising a pressure-relief valve for release of excessive pressure in the container and a filter arranged to permit egress of gas through the filter, inhibit egress of liquid from the container and to inhibit ingress of contaminants into the container through the pressure relief valve. A dispensing assembly for use is a spray dispenser is also provided.

FIELD

The present invention relates to a spray dispenser, particularly (butnot exclusively) for use in dispensing sterile fluids.

BACKGROUND

GB2391862 discloses a dispenser which is effective for dispensingsterile liquids. The dispenser comprises a collapsible inner vessel fromwhich liquid is dispensed using a trigger-actuated pumping arrangementand a dip tube which extends to the bottom of the inner vessel, theinner vessel being located in a rigid outer bottle. As liquid isdispensed from the collapsible vessel, the vessel collapses because noingress of air is permitted into the vessel through the dispensingarrangement. Air is permitted to enter the space between the innervessel and outer bottle. Such dispensers may be sterilised by fillingthe dispenser with fluid, sealing the dispenser in an air-tight bag (andoptionally sealing this air-tight bag within a second and optionally athird air tight bag) and then irradiating the dispenser to sterilise thedispenser and its contents. In certain circumstances, irradiation maycause unwanted side effects. For example, irradiation causes unwantedgeneration of gas in the container. Such generation of gas may causeunwanted bulging of the container due to a pressure build-up in thecontainer and the container being made of sub-standard materials. Forexample, the bottom of the outer container may bulge outwards, producinga bottle with a rounded bottom which cannot stand. Alternatively,leakage may be observed from one of several potentially weak points;unwanted leakage may be observed through the dispensing valve.

The present invention seeks to mitigate one or more of the problemsmentioned above and/or to provide an improved spray dispenser.

SUMMARY

In accordance with a first aspect of the present invention, there isprovided a spray dispenser comprising a container for holding a liquidto be dispensed and a dispensing assembly for extracting liquid fromsaid container, the dispensing assembly comprising a pressure-reliefvalve for release of excessive pressure in the container and a filterarranged to permit egress of gas from the container through the filterand through the pressure-relief valve, the filter inhibiting egress ofliquid from the container through the filter.

The spray dispenser of the present invention provides a dispenserparticularly suitable for the dispensing of sterile liquids because itpermits release of excessive pressure (such as may occur when the liquidcontained in the container is irradiated to sterilise the container andits contents), the valve closing when said pressure has been relieved,thus inhibiting ingress of contaminants into the container. Furthermore,the filter inhibits egress of liquid from the container, thereforedecreasing the likelihood of any spillage in the event that anoverpressure occurs in the container. It is preferred that thepressure-relief valve is closed in the absence of excessive pressure toinhibit ingress of air and contaminants into the container. This is ofparticular benefit if it is undesirable to allow air into the container,for example, if the container comprises a collapsible liquid-containingportion.

Filters which are typically used in the spray dispenser of the presentinvention also typically inhibit ingress of contaminants into thecontainer through the pressure relief valve.

For the avoidance of confusion, it is hereby stated that thepressure-relief valve is not a dispensing valve (i.e. a valve throughwhich liquid is, in use, dispensed). The spray dispenser of the presentinvention will typically be provided with a dispensing valve in additionto the pressure-relief valve.

The filter typically prevents passage therethrough of liquid at thepressures which typically build-up within a container. These pressuresare discussed below.

The filter may be permeable to gas and impermeable to liquids.

Those skilled in the art will realise that the filter will beimpermeable to the liquid held within a container at the pressuresgenerated when such filled containers are subjected to sterilisingirradiation. Typical pressures are those generated when 1 litre ofisopropyl alcohol contained within a container designed to contain 1litre of liquid is subjected to 25 kGy of gamma radiation emitted by acobalt source. The headspace above 1 litre of liquid is estimated to beapproximately 20-30 ml.

Those skilled in the art will readily be able to determine whether afilter is impermeable to liquid by observing whether liquid permeatesthrough a filter.

Those skilled in the art will realise that the liquid is not anessential (but rather an optional) part of the spray dispenser of thepresent invention.

It is preferred that the filter is in a gas flow path between theinterior of the container and the pressure-relief valve. Alternatively,the pressure-relief valve may be in a gas flow path between the interiorof the container and the filter.

The filter preferably inhibits ingress of particulate into thecontainer. The filter may comprise pores which permit passagetherethrough of vapour, but inhibit passage therethrough of particulate.It is preferred that the filter inhibits passage therethrough ofparticles having a mean dimension of greater than 50 microns, morepreferably greater than 5 microns and further more preferably 0.5microns. The pores may have a mean greatest dimension of less than 10microns, preferably less than 5 microns, more preferably less than 1micron and further more preferably less than 0.3 microns. Alternatively,the filter may be substantially free of pores.

The filter may comprise a membrane. The membrane may be hydrophobic, andmay comprise a hydrophobic material such as polytetrafluoroethylene.Alternatively, the membrane may be oleophobic.

The filter may be located within a filter housing.

The container may comprise a fluid containment portion which may becollapsible (for example, the container may comprise a collapsible bag,typically made from plastics material). The container may comprise acontainer seal-forming surface. The spray dispenser may comprise asealing member for forming a seal against the container seal-formingsurface to inhibit ingress of air into the container. The sealing membermay be provided as part of the dispensing assembly.

The container may be sufficiently rigid that it does not collapse whenliquid is extracted therefrom.

The sealing member may be annular.

The container seal-forming surface may be provided by a collar. If thecontainer comprises a collapsible fluid containment portion, it ispreferred that the collar is more rigid than the fluid containmentportion.

The pressure-relief valve may comprise any suitable one-way valve. Thepressure-relief valve may comprise a spring valve, a diaphragm valve, abutterfly valve, a swing valve, a ball check valve or a duckbill valve.The duckbill valve is preferred because it may show good performance.The operation of the pressure-relief valve should preferably not beadversely affected by gamma radiation, such as is typically used tosterilise the contents of a container. The characteristics of thepressure-relief valve may be selected so that, after releasing excesspressure within the container, the valve closes appropriately to inhibitingress of air into the container. This is particularly preferred, forexample, if the container is collapsible.

As mentioned above, a container is typically subjected to a 25 kGysterilising dose. For example, if the pressure-relief valve comprises aduckbill valve, the duckbill valve should be made from a material whoseperformance is not affected by the sterilisation process to the extentthat the duckbill valve does not function appropriately. For example,duckbill valves may be made from elastomers whose properties are notsignificantly affected by irradiation. Details of such elastomers willbe readily apparent to those skilled in the art. For example, details ofsuch elastomers may be found in “The effects of sterilization methods onplastics and elastomers: the definitive user's guide and databook”,edited by L. K. Massey, published by William Andrew, 2004.

The spray dispenser may be provided with a closure means, such as a cap,for inhibiting access to the container. One or both of thepressure-relief valve and filter may be associated with the closuremeans. The dispensing assembly may comprise the closure means. Forexample, the closure means may be provided with both the pressure-reliefvalve and the filter.

The spray dispenser preferably comprises a housing for enclosing thecontainer. The housing may support the container; this is particularlypreferred if the container comprises a collapsible fluid containingportion. The closure means, if present, may be removably attachable tothe housing. This is particularly preferable if the closure means isprovided as part of the dispensing assembly. For example, the closuremeans may be provided with a configuration which interacts with acorresponding configuration provided on the housing so as to permitattachment of the closure means to the housing.

The dispensing assembly may comprise a pressure means for creating adifferential pressure to dispense fluid from the container. Thedispensing assembly may comprise an actuator, such as a trigger pumpingarrangement.

The dispensing assembly may comprise a dispensing line, such as anelongate tube.

The dispensing line, if present, may be in a gas-tight sealingengagement with a dispensing line sealing means. The dispensing linesealing means inhibits ingress of air into the container. The dispensingline sealing means may be provided by the above-mentioned sealingmember. The dispensing line sealing means may be provided as part of thedispensing assembly.

Alternatively, the dispensing line sealing means may be provided by aseparate component. For example, the dispensing line sealing means maybe in the form of an apertured plate, the plate being provided with anaperture which receives the dispensing line in sealing engagement. Theapertured plate may be associated with (and may be adjacent or proximateto) the closure means (if present).

The dispensing assembly may comprise one or both of a dispensing lineand a pressure means for creating differential pressure to dispensefluid.

The dispensing assembly may be mountable onto, and optionallydismountable from, the container.

In accordance with a second aspect of the present invention, there isprovided a dispensing assembly for use in the spray dispenser assemblyof the first aspect of the invention. The dispensing assembly of thesecond aspect of the present invention may comprise those featuresmentioned above in relation to the spray dispenser of the first aspectof the present invention.

In accordance with a third aspect of the present invention, there isprovided a dispensing assembly for use in a spray dispenser to dispenseliquid from a container, the dispensing assembly comprising apressure-relief valve for release of excessive pressure in a containerto which the dispensing assembly is fitted and a filter arranged topermit egress of gas from the container through the filter and throughthe pressure-relief valve, the filter inhibiting egress through thefilter of liquid from a container to which the dispensing assembly isfitted.

For the avoidance of confusion, it is hereby stated that thepressure-relief valve is not a dispensing valve (i.e. a valve throughwhich liquid is, in use, dispensed). The dispensing assembly of thepresent invention will typically be provided with a dispensing valve inaddition to the pressure-relief valve.

The filter typically used in the dispensing assembly is capable ofinhibiting ingress of contaminants into a container to which thedispensing assembly is fitted.

The dispensing assembly of the third aspect of the present invention maycomprise those features described above in relation to the spraydispenser of the first aspect of present invention. Furthermore, thedispensing assembly of the third aspect of the present invention may besuitable for use in the spray dispenser of the first aspect of thepresent invention.

For example, the dispensing assembly of the third aspect of the presentinvention may comprise a closure means for inhibiting access to acontainer. The dispensing assembly may comprise a dispensing aperture.The dispensing assembly may comprise a dispensing line in fluidcommunication with the dispensing aperture. The dispensing assembly maycomprise a pressure means for creating differential pressure to dispenseliquid.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be described by way of example only withreference to the following figures of which:

FIG. 1 is an exploded view of part of a known dispenser;

FIG. 2 is a side-on view of part of an example of a dispenser inaccordance with the present invention;

FIG. 3 is a perspective view of the part of the dispenser shown in FIG.2;

FIG. 4 is a view from below of the part of the dispenser shown in FIGS.2 and 3;

FIG. 5 is a quasi-sectional view of the part of the dispenser of FIGS. 2to 4; and

FIG. 6 is a cross-sectional view of a portion of the dispenser of FIGS.2 to 5 showing the pressure-relief valve and the filter.

FIG. 7 is a cross-sectional view of a portion of the dispenser of FIGS.2 to 5 showing the pressure-relief valve and the filter.

FIG. 8 is a partial schematic side view of the dispenser of FIGS. 2 to 5connected to a bottle according to an embodiment.

DETAILED DESCRIPTION

FIG. 1 shows an exploded view of part of a known spray dispenser, asdescribed in GB2391862. For convenience, the operation of the knownspray dispenser is now briefly described. The known spray dispenser 1comprises a flexible, inner vessel 6 in the form of a bag of a plasticsmaterial, formed with a convex bottom 7. The inner vessel 6 has a neckregion 5 in which the plastics material is welded to a collar 8, thusforming an annular weld 10 around the circumference of the collar 8. Abung 12 is inserted into the collar 8, thus forming a seal between bungand collar. A dip tube (shown as dotted line 9 in FIG. 1) is insertedinto the vessel 6 via an aperture in bung 12, there being a seal formedbetween the dip tube 9 and the bung 12 due to diameter of the dip tubeand the resilient nature of the bung. The inner vessel 6 is providedwith liquid (not shown) to be dispensed therefrom. The inner vessel 6 issupported by an outer container in the form of a substantially rigid,generally cylindrical plastics bottle 2. The plastics bottle 2 abuts anannular lip 14 provided on collar 8, therefore providing support to theinner vessel 6. The plastics bottle 2 is provided with an aperture 16which facilitates the passage of air into the plastics bottle and intothe space surrounding the inner vessel 6.

The dip tube 9 is associated with a trigger assembly (not shown). Thetrigger assembly used in the prior art device conforms in general toknown trigger-actuated pressure pump arrangements. Actuation of thetrigger assembly creates a differential in pressure which draws liquidalong the dip tube and dispenses it as a spray. The arrangement of thebung and trigger arrangement ensures that any exhaust air or backpressure does not result in ambient air being drawn into the collapsiblecontainer. This inhibits contamination of the contents of the vessel 6by external contaminants. Because the inner vessel 6 collapses as liquidis dispensed, little or no back pressure exists in the flexible innervessel. Aperture 16 prevents a partial vacuum being created between theinterior wall of plastics bottle 2 and the vessel 6 as the vessel 6collapses.

An example of a dispenser in accordance with the present invention willnow be described with reference to FIGS. 2 to 6. The dispenser comprisesa collapsible inner vessel 156 similar to that described above inrelation to the prior art and as described in GB2391862. The dispenseralso comprises a substantially rigid housing 150 (partially shown inphantom) in the form of a bottle. The bottle is very similar to thatdescribed above in relation to the prior art and as described inGB2391862. Whilst the collapsible inner vessel and rigid bottle ofGB2391862 were manufactured separately, the collapsible inner vessel andrigid bottle of the example of the spray dispenser of the presentinvention are made using a single co-extrusion, blow-moulding process.The co-extruded arrangement of the collapsible inner vessel 156 andrigid bottle 150 is commercially available as part of the SteriShieldDelivery System (Shield Medicare Limited, Farnham, UK). The inner vesselin the SteriShield system does not have a collar separate from thecollar of the rigid bottle.

The dispenser of the present invention comprises a dip tube (101) whichextends from the bottom of the collapsible container (not shown) into adispenser head (102). The dip tube (101) passes through cap (106) via anaperture (not shown) in a plate (103). The dip tube (101) is in sealingengagement with the plate (103) at the aperture (not shown) so as toinhibit passage of air into the container of liquid. The dip tube (101)is in fluid communication with dispenser channel (118). Dispenserchannel (118) is provided with a ball valve (108), the operation ofwhich will be described below. Dispenser channel (118) is in fluidcommunication with dispenser channel (119) which has a nozzle (109) atone end. Nozzle (109) comprises a nozzle aperture (110) for the spraydispensing of fluid and a spray control member (111). The spray controlmember (111) is mounted relative to the nozzle aperture (110) so thatsaid member is operable to control the spray emitted from the dispenser,as is well-known to those skilled in the art. The spray dispenserfurther comprises a trigger (112) which is associated with a piston(113). A spring (114) biases the piston and trigger into a forwardposition.

Liquid is dispensed from the dispenser essentially as described above inrelation to the prior art dispenser. Pulling the trigger (112) causesliquid to be pumped from the dispenser as a spray. On releasing thetrigger, the spring 114 urges the piston 113 into the forward position.This urges liquid up the dip tube (101) ready to be dispensed on thenext spray stroke. The ball valve (108) operates so as to permit fluidflow up through the dip tube (101) into the dispenser head (102) fordispensing, but inhibits ingress of contaminants into the container viathe dip tube (101).

The arrangement of the dip tube (101) and sealing member (107) isslightly different from that shown above in FIG. 1 in relation to theprior art. The sealing member (107) comprises an annular washer which,in use, engages with the annular, uppermost surface of the neck of thebottle (not shown) to produce a seal.

The arrangement and operation of the pressure-relief valve and filterare now described. A venting aperture (104) is provided in plate (103).The venting aperture (104) is in gas flow communication with thepressure-relief valve (115) and filter (105), with the filter being in agas flow path between the venting aperture (104) and the pressure-reliefvalve (115). The filter (105) is located in a filter housing (116) tofacilitate ease of handling. The filter is a membrane (130) ofhydrophobic material (Gore(R) membrane, W. L. Gore and Associates,Newark, USA), with 0.2 micron pores (131) therein. The filter housing(116) is located in a space formed in the valve housing (117). Such anarrangement facilitates ease of placement of the filter relative to thevalve. The pressure relief valve 115 is a duck-bill valve which iseffectively trapped in place by two parts 117 a, 117 b of the valvehousing 117. The operation of the pressure-relief valve 115 will now beexplained briefly. The pressure-relief valve 115 comprises twoelastically deformable lips 120, 121 which, in the default state, areurged against one another into a closed state, thus inhibiting ingressof air and contaminants into the container. When there is anover-pressure in a container, the lips 120, 121 are urged apart so thata gas associated with the over-pressure passes out of the vessel througha valve aperture 122, thus relieving the pressure. The one-way valve 115therefore permits egress of gas associated with the over-pressure andnaturally closes in the absence of over-pressure, therefore inhibitingingress of air and contaminants into the container. The duckbill valveis made from an elastomer which prevents backflow leakage when minimalbackpressure is applied. Furthermore, the elastomer is resilient togamma radiation which is used to sterilise the container and itscontents. The duckbill valve also has the advantage that it can beinstalled easily into a hole and sealed. Those skilled in the art willrealise that the properties of the valve (e.g. the pressure differentialat which the valve opens to release pressure and the backpressure atwhich the valve closes) may be readily optimised by changing thethickness of the elastomer, the shape of the valve and the elastomerfrom which the valve is made.

The filter 105 provides further protection against ingress ofcontaminants, and also allows passage therethrough of vapour generatedby an overpressure but the filter prevents egress of liquid from thecontainer through the filter. The filter is advantageously sited in aflow path between the valve and the contents of the vessel. Whilst it ispossible to site the valve in a flow path between the filter and thecontents of the vessel, this is not so desirable because the filter maybe prone to clogging, which may inhibit egress of vapour in the event ofoverpressure.

Those skilled in the art will realise that the present invention is notlimited to the type of dispenser mentioned above (i.e. one whichcomprises a collapsible container sealed to the dispensing mechanism).

Those skilled in the art will also realise that the present invention isnot limited to the particular type of valve shown in the example above.For example, a spring-biased pressure relief valve or a reed valve maybe used.

It will be apparent to those skilled in the art that an actuator otherthan a trigger may be used. For example, a button or the like may beused.

Where in the foregoing description, integers or elements are mentionedwhich have known, obvious or foreseeable equivalents, then suchequivalents are herein incorporated as if individually set forth.Reference should be made to the claims for determining the true scope ofthe present invention, which should be construed so as to encompass anysuch equivalents. It will also be appreciated by the reader thatintegers or features of the invention that are described as preferable,advantageous, convenient or the like are optional and do not limit thescope of the independent claims.

What is claimed is:
 1. A spray dispenser comprising a container forholding a liquid to be dispensed and a dispensing assembly forextracting liquid from said container, the dispensing assemblycomprising a pressure-relief valve for release of excessive pressure inthe container and a filter arranged to permit egress of gas from thecontainer through the filter and through the pressure-relief valve, thefilter inhibiting egress of liquid from the container through thefilter, the pressure-relief valve being closed in the absence ofexcessive pressure to inhibit ingress of air and contaminants into thecontainer wherein: the filter is in a gas flow path between the interiorof the container and the pressure-relief valve, or the pressure-reliefvalve is in a gas flow path between the interior of the container andthe filter.
 2. A spray dispenser according to claim 1, wherein thefilter inhibits ingress of particulate into the container.
 3. A spraydispenser according to claim 2, wherein the filter comprises pores whichpermit passage therethrough of gas, but inhibit passage therethrough ofparticulate.
 4. A spray dispenser according to claim 1, wherein thefilter is located within a filter housing.
 5. A spray dispenseraccording to claim 1, wherein the container comprises a fluidcontainment portion which is collapsible.
 6. A spray dispenser accordingto claim 5, wherein the container comprises a collar which is more rigidthan the fluid containment portion.
 7. A spray dispenser according toclaim 1, wherein the container comprises a container seal-formingsurface and the spray dispenser comprises a sealing member for forming aseal against the container seal-forming surface to inhibit ingress ofair into the container.
 8. A spray dispenser according to claim 7,wherein the dispenser assembly comprises the sealing member. 9.(canceled)
 10. A spray dispenser according to claim 1, wherein thepressure-relief valve comprises a diaphragm valve, a spring valve, abutterfly valve, a swing valve, a ball check valve or a duckbill valve.11. A spray dispenser according to claim 1, wherein the spray dispenseris provided with a closure for inhibiting access to the container.
 12. Aspray dispenser according to claim 11, wherein the dispensing assemblycomprises the closure.
 13. A spray dispenser according to claim 11,wherein the closure is provided with both the pressure-relief valve andthe filter.
 14. A spray dispenser according to claim 1 comprising ahousing for enclosing the container.
 15. A spray dispenser according toclaim 14, wherein the housing supports the container.
 16. A spraydispenser according to claim 14, comprising a closure being removablyattachable to the housing.
 17. (canceled)
 18. A spray dispenseraccording to claim 1, the dispensing assembly comprising a dispensingline, wherein the dispensing line is in a gas-tight sealing engagementwith a dispensing line seal provider.
 19. (canceled)
 20. A spraydispenser according to claim 18, wherein the dispensing line sealprovider is in the form of an apertured plate, the plate being providedwith an aperture which receives the dispensing line in sealingengagement.
 21. (canceled)
 22. A spray dispenser according to claim 1,wherein the dispensing assembly is mountable onto, and dismountablefrom, the container.
 23. A spray dispenser according to claim 1, thefilter comprising a hydrophobic membrane.
 24. (canceled)
 25. Adispensing assembly for use in a spray dispenser to dispense liquid froma container, the dispensing assembly comprising a pressure-relief valvefor release of excessive pressure in a container to which the dispensingassembly is fitted and a filter arranged to permit egress of gas fromthe container through the filter and through the pressure-relief valve,the filter inhibiting egress of liquid from a container to which thedispensing assembly is fitted, the pressure-relief valve being closed inthe absence of excessive pressure in a container to which the dispensingassembly is fitted so as to inhibit ingress and air and contaminantsinto a container to which the dispensing assembly is fitted, wherein thefilter is in a gas flow path between the interior of the container towhich the dispensing assembly is fitted and the pressure-relief valve,or the pressure-relief valve is in a gas flow path between the interiorof the container to which the dispensing assembly is fitted and thefilter.